A Novel Description of Breast Anatomy Indicates the Need for New Surgical Approaches

Abstract

Mastectomy remains a major treatment for breast cancers and prophylaxis for carriers of the BRCA genes, yet the amount of tissue removed is variable across surgical approaches. The anatomical and surgical literatures provide conflicting and incomplete descriptions of breast gross anatomy. In order to clarify this anatomy, we dissected 6 male and 15 female human cadaveric specimens. We found that the mammary glandular tissue is constrained to a membrane‐bound, central structure referred to as the corpus mammae in the surgical literature, and not dispersed throughout the breast as described in the anatomical literature, consistent with other epidermally derived glands of the body. The major fasciae of the human ventral body wall, including the superficial fatty Camper’s fascia and the deeper membranous Scarpa’s fascia, both contribute to the structure of the breast. Based on these findings, we propose that during embryological development the mammary gland grows dorsally from the integument, pushing Camper’s and Scarpa’s fasciae ahead of it. When the mammary gland reaches the rigid thoracic wall, the gland grows laterally, pulling along Camper’s fascia to create the fat of the breast. Ventrally Scarpa’s fascia becomes a double layer that creates the shape of the breast and dorsally Scarpa’s forms a circummammary ligament that 1) stabilizes the breast against the thoracic wall and 2) is continuous with Scarpa’s fascia on the rest of the ventral body wall at the inframammary fold. The suspensory ligaments of the breast represent the typical, albeit thickened, septations between compartmentalized fat lobules found consistently throughout the human body, and do not attach to the skin. Instead, these ligaments attach to Scarpa’s fascia. We propose replacing surgical approaches that remove the entire breast with more targeted procedures focused on removing the gland only. Since the glandular material is constrained to the corpus mammae, in low‐grade cancers and prophylaxis surgeons can utilize fascial planes to remove only the gland while protecting the rest of the breast. Such a procedure could allow the patient to maintain most of the breast, thereby potentially reducing physical and emotional trauma.